i know the general rule is -2 degrees for every 50shot nitrous.

is this -2 degrees from stock timing? or is it -2 degrees from best advance timing u can get?

 

Whatever your motor runs best at. 95% of SBC's run best with 32* to 38* total ...find out what works best for you N/A then subtract for the amount of nitrous you plan on using.

 

my engine has the stock timing atm, is that the 36-38 u talk of?

so the idea is, find the most advance timing i can get withotu knock, and subtract 2 for every 50 shot?

 

yes

 

Grrr… no, it depends on how it's setup. For example NX doesn't recommend any retard for their basic setup, but is pretty adamant about running cooler plugs, and this works without any problems. If it was me (and I've been there), I'd find where the car runs the best NA and then figure out how to run that setting with the N2O. FWIW, timing is not that important with N2O, you'll pretty much make the best power over a fairly wide range while spraying, the only important thing is to keep away from detonation.

 

Or you could try running the stock plugs and retard the timing. Like you said, it's all about staying away from detonation. By doing this you can run the best NA as well.

 

You're looking for trouble using this method.

The timing setting that gives maximum performance is NOT
What ever maximum setting that allows the most advance without pinging.

Doing this will generally result in over advanced timing.

If you want to find out what timing setting your motor need to make maximum performance, visit a drag strip
on a test and tune day and try different settings noting
what setting results in the best MPH on the time slip.
(maximum horsepower) then back off the timing for NOS from there using your rule of thumb as a base line.
The ET on a time slip is more of an indicator of traction and driving skill than HP.

 

on my fogger set up the booklet says 4-6* for the 250 shot 6-8* on the 300 and 350 shot , 8-10*on the 400 shot and 10 + over that

mike

 

I agree, but a dyno would be a more accurate way of tuning. As you know, there are a lot of variables when you make a pass.

 

i have a custom setup,

a zex dry kit and the nos wet kit combined into it,

i follow both companies, they both say -2degrees for every 50, and also say 2 stage colder spark plugs, both companies are saying the same.

should i just find my max advance and subtract two?

im not looking for most power gain, but safest i can do.

 

Then why are you even asking the question? Detonation breaks things, too much timing can cause it, so run a few degrees less then where you feel absolutely safe and you're good.

 

what i mean is what the company says is safe.